The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example, lactate, cholesterol, and bilirubin should be monitored in certain individuals. In particular, determining glucose in body fluids is important to diabetic individuals who must frequently check the glucose level in their body fluids to regulate the glucose intake in their diets.
Those who have irregular blood glucose concentration levels are medically required to regularly self-monitor their blood glucose concentration level. The purpose of monitoring the blood glucose concentration level is to determine the blood glucose concentration level and then to take corrective action, based upon whether the level is too high or too low, to bring the level back within a normal range. The failure to take corrective action can have serious implications. When blood glucose levels drop too low—a condition known as hypoglycemia—a person can become nervous, shaky, and confused. That person's judgment may become impaired and they may eventually faint. A person can also become very ill if their blood glucose level becomes too high—a condition known as hyperglycemia. Both conditions, hypoglycemia and hyperglycemia, are potentially life-threatening emergencies.
One method of monitoring a test subject's blood glucose level is with a portable, hand-held blood glucose testing device. In order to check the blood glucose level with the testing device, a drop of blood is obtained from the fingertip using a lancing device. A typical lancing device contains a needle lancet to puncture the skin of a finger. This monitoring procedure often is repeated several times a day. Because this procedure can be painful, instruments have been developed to obtain blood from alternate sites other than a fingertip such as arms, legs and palm of the hand. Although obtaining a blood sample from an alternate site is less painful, Alternative Site Testing (AST) results in intrinsic testing problems that have not previously been addressed.
Typically, the test subject uses the hand-held blood testing device to determine the glucose concentration in the blood sample. The test subject then writes the determined concentration into a log book along with other information, such as the date and time. This log book is then provided to a physician or other health care professional who analyzes the provided data to determine the proper course of action for the test subject. Thus, if the data in the log book is flawed, the diagnosis and course of action generally will be flawed as well.
Utilizing AST increases the potential for improper glucose concentrations to be obtained. For example, to help ensure a proper determination of the glucose concentration, AST should not be used for approximately two hours after a meal, insulin injection, or exercise. Though test subjects are generally informed of these precautions by their health care professional(s), test subjects have been known to disregard or forget these precautions. Thus, even if the test subject properly utilizes the blood testing device and accurately records the data into their log book, the data may still be flawed.
Therefore, there exists a need for a system that distinguishes an alternative-site test result from a standard-site test result.